Method-Release of monocyte TNF-a after in vitro stimulation with coal mine dust, silica, and endotoxin was measured in 104 retired miners and was related to stage of CWP (chest radiograph) and cumulative exposure.

A subgroup of 46 miners was screened by high resolution computed tomography (HRCT).

Prospective analysis of TNF-a (40 out of 104 miners involved in the previous TNF-a study) was done by relating initial TNF-a to five year progression of CWP measured by comparison of paired chest radiographs.

Results

As observed previously, dust stimulated release of TNF-a was increased in miners, especially in the early stages of pneumoconiosis.

Cumulative exposure was related to pneumoconiotic stage but not to release of TNF-a.

This excluded TNF-a as an exposure marker.

Initial concentrations (1987) of TNF-a were related to later progression of CWP.

Miners who showed abnormally high dust stimulated release of TNF-a had an increased risk of progression in CWP.

Conclusions-These results show (a) the significant involvement of TNF-a in pneumoconiosis in humans induced by coal dust and (b) that this routine test possibly constitutes a powerful tool to estimate individual prognosis of pneumoconiotic disease, even after the end of occupational exposure.